Seal device and method for assembling a guide block in a gland of the seal device

ABSTRACT

A seal device for a rotary shaft includes a sleeve, a gland, a ring, a guide block, and a fixing member. The guide block has an outer block surface extending circumferentially and abutting against a portion of an inner gland surface of the gland, and an inner block surface extending circumferentially and opposite to the outer block surface. The outer block surface has two circumferentially opposite outer ends. The inner block surface has two circumferentially opposite inner ends. The guide block further has two opposite end faces each of which connects one of the outer ends to one of the inner ends. The inner ends subtend an angle of not larger than 90° at a center line of the gland. At least one of the end faces lies in a plane line that is substantially tangent to an outer peripheral face of the ring.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a seal device, more particularly to a sealdevice mounted between a rotary shaft and a stuffing box of a mixingmachine. The invention also relates to a method for assembling a guideblock in a gland of the seal device.

2. Description of the Related Art

A seal device is usually mounted in a stuffing box of of a mixingmachine so as to prevent leakage of fluid stirred in a stirring tank ofthe mixing machine due to high pressure in the stirring tank.

The seal device is usually classified into a single seal device and adual seal device. No matter whether the seal device is single or dual, agland of the seal device is provided with a fluid passage for permittingbuffer/barrier fluid or flush fluid to flow therethrough. A guide memberis provided in the fluid passage and is inclined so as to guide thefluid to flow smoothly in the fluid passage.

Referring to FIG. 1, a conventional seal device includes a gland 11formed with an inlet 111 and an outlet 112 aligned with each other, anda guide member 12 annularly extending between the inlet 111 and theoutlet 112 within a fluid passage 113. Since the guide member 12occupies almost half of the fluid passage 113, the heat produced duringoperation cannot be removed effectively.

Referring to FIG. 2, another conventional seal device includes a gland21 formed with an inlet 211 and an outlet 212, and a guide member 22disposed between the inlet 211 and the outlet 212 within a fluid passage213. The guide member 22 has a middle portion 221 connected to an innerperipheral surface of the gland 21, and two curved guiding portions 222oppositely extending from the middle portion 221 so as to guidebuffer/barrier fluid entering from the inlet 211 to flow through thefluid passage 213 and to exit from the outlet 212. However, turbulenceand/or heat aggregation may occur in an area between the guidingportions 222, which in turn causes the guide member 22 to deform,especially when an external pressure is applied into the fluid passage213.

Referring to FIG. 3, still another seal device disclosed in TaiwaneseUtility Model No. M179519 includes a gland 32 formed with a positioninghole 322 communicated with a fluid passage 321, a guide block 31disposed within the fluid passage 321, and a fixing member 33 insertedinto the positioning hole 322 and engaging the guide block 31. The guideblock 31 has two oppositely inclined end faces 312, and an inner curvedsurface 311 extending between the inclined end faces 312 so that thebuffer/barrier fluid entering from two inlets 323 can be guided by theinclined end faces 312 of the guide block 31 so as to flow through thefluid passage 321 and exit from an outlet 325 to remove the heatproduced due to the rotation of a rotary shaft 36.

Since the plane lines (S1) in which the inclined end faces 312 lie arenot tangent to an outer peripheral face of a sleeve 35, thebuffer/barrier fluid entering from the inlets 323 is sprayed onto aninner peripheral surface of the gland 32 prior to flowing smoothly inthe fluid passage 321. In other words, the buffer/barrier fluid can notbe effectively guided by the guide block 31 to flow smoothly in thefluid passage 321. Furthermore, since the fixing member 33 engages theguide block 31 merely at an end portion thereof, it can not be firmlypositioned and engaged to the guide block 31. Therefore, the guide block31 is liable to shake or the fixing member 33 is liable to break duringoperation of the rotary shaft 36, which in turn causes leakage of thebuffer/barrier fluid.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a sealdevice that can overcome at least one of the aforementioned shortcomingsof the prior art. Another object of the present invention is to providea method for assembling a guide block in a gland of the seal device.

In a first aspect of this invention, a seal device for a rotary shaftincludes a sleeve, at least one gland, at least one ring, a guide block,and a fixing member. The sleeve is for extension of and connection withthe rotary shaft. The gland has an inner gland surface defining acentral hole for extension of the sleeve, and a fluid passage extendingannularly around the central hole. The ring is disposed around thesleeve within the central hole. The guide block is disposed within thefluid passage and has an outer block surface extending circumferentiallyand abutting against a portion of the inner gland surface, and an innerblock surface extending circumferentially and opposite to the outerblock surface. The outer block surface has two circumferentiallyopposite outer ends. The inner block surface has two circumferentiallyopposite inner ends. The guide block further has two opposite end faceseach of which connects one of the outer ends to one of the inner ends.The inner ends subtend an angle of not larger than 90° at a center lineof the gland. At least one of the end faces lies in a plane line that issubstantially tangent to an outer peripheral face of the ring. Thefixing member is connected to the guide block and is fixed to the gland.

In a second aspect of this invention, a seal device for a rotary shaftincludes a sleeve, at least one gland, a guide block, a fixing member,and a welding material. The sleeve is for extension of and connectionwith the rotary shaft. The gland has inner and outer gland surfaces, anda fixing hole that is stepped to form small and large cross-sectionportions extending radially and respectively through the inner and outergland surfaces. The inner gland surface defines a central hole forextension of the sleeve, and a fluid passage extending annularly aroundthe central hole. The guide block is disposed within the fluid passageand has an outer block surface extending circumferentially and abuttingagainst a portion of the inner gland surface, and an inner block surfaceextending circumferentially and opposite to the outer block surface. Thefixing member is connected to the guide block and extends through thesmall and large cross-section portions. The fixing member is receivedfittingly in the small cross-section portion. The welding material fillsthe large cross-section portion around the fixing member, therebyretaining the fixing member in the fixing hole.

In a third aspect of this invention, there is provided a method forfixing a guide block in a gland of a seal device for a stuffing box, inwhich the gland has an inner gland surface that defines a central holeand a fluid passage extending annularly around the central hole, and anouter gland surface surrounding the inner gland surface. The methodincludes the steps of: providing the gland with a fixing hole thatextends radially through the inner and outer gland surfaces; disposingthe guide block in the fluid passage; inserting a fixing member into thefixing hole; connecting the fixing member to the guide block; placing anouter block surface of the guide block in abutment with the inner glandsurface; filling a welding material in the fixing hole around the fixingmember, thereby retaining the fixing member in the fixing hole; andcutting a portion of the fixing member that extends outwardly of thefixing hole, followed by a grinding process to make the fixing memberflush with the outer gland surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will becomeapparent in the following detailed description of the preferredembodiments with reference to the accompanying drawings, of which:

FIG. 1 is a sectional view of a conventional seal device;

FIG. 2 is a schematic view of another conventional seal device;

FIG. 3 is a schematic view of still another conventional seal device;

FIG. 4 is a sectional view of a preferred embodiment of a seal deviceaccording to this invention;

FIG. 5 is a sectional view of a guide block and a fixing member used inthe preferred embodiment;

FIG. 6 is a flow chart of a preferred embodiment of a method for fixinga guide block in a gland of a seal device according to this invention;

FIG. 7 is a sectional view of a semi-product made by the preferredembodiment of FIG. 6;

FIGS. 8 to 11 are sectional views illustrating various practice statesof the preferred embodiment of FIG. 4;

FIG. 12 is a sectional view of another example of the guide blockconnected to the fixing member; and

FIG. 13 is a sectional view of still another example of the guide blockconnected to the fixing member.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 4 and 5, the preferred embodiment of a seal device 6according to this invention is mounted between a stuffing box and arotary shaft 7 of a mixing machine (not shown), and includes a sleeve61, a gland 62, a rotary ring 63, a guide block 51, a fixing member 52,and a welding material 53.

The sleeve 61 is for extension of and connection with the rotary shaft7.

The gland 62 has an inner gland surface 626, an outer gland surface 627extending around the inner gland surface 626, and a fixing hole 623 thatis stepped to form small and large cross-section portions 624, 625extending radially and respectively through the inner and outer glandsurfaces 626, 627. The inner gland surface 626 defines a central holefor extension of the sleeve 61, and a fluid passage 621 extendingannularly around the central hole. The gland 62 is further formed with afirst hole 622, a second hole 622′, and a third hole 622″, which arefluidly communicated with the fluid passage 621. The first and secondholes 622, 622′ are proximate to the guide block 51, and the third hole622″ is opposite to the guide block 51.

The rotary ring 63 is disposed around the sleeve 61 within the centralhole. The rotary ring 63 has an outer peripheral face 631 formed with aplurality of annularly spaced apart recesses 632 and projections 633.

It should be noted that two or more glands 62 can be used in series, andthat the number of the rotary ring 63 may be one or more.

The guide block 51 is disposed within the fluid passage 621 and has anouter block surface 511 extending circumferentially and abutting againsta portion of the inner gland surface 626, and an inner block surface 512extending circumferentially and opposite to the outer block surface 511.The outer block surface 511 has two circumferentially opposite outerends 5111. The inner block surface 512 has two circumferentiallyopposite inner ends 5121. The guide block 51 further has two oppositeend faces 513 each of which connects one of the outer ends 5111 to oneof the inner ends 5121. The inner ends 5121 subtend an angle (θ1), whichis defined by two lines (L2, L3) passing through a center line (L1) ofthe gland 62, of not larger than 90° at the center line (L1) of thegland 62. The end faces 513 respectively lie in plane lines (L7, L8)that are substantially tangent to an outer peripheral face of the rotaryring 63. Specifically, each of the end faces 513 has an inclined face514 lying in a corresponding one of the plane lines (L7, L8) andadjoining a corresponding one of the outer ends 5111 of the outer blocksurface 511, and a cut face 515 extending from the inclined face 514 toa corresponding one of the inner ends 5121 of the inner block surface512.

The fixing member 52 is connected to the guide block 51 and is fixed tothe gland 62. The fixing member 52 extends along a radial line (L6) thatpasses through the center line (L1) of the gland 62. In this embodiment,the fixing member 52 is a fixing rod that has an external thread 521,and the guide block 51 has a threaded hole 516 extending inwardly fromthe outer block surface 511. The fixing rod is engaged in the threadedhole 516. Alternatively, the fixing member 52 and the guide block 51 canbe formed as one piece. The fixing member 52 extends through the smalland large cross-section portions 624, 625 and is received fittingly inthe small cross-section portion 624. The large cross-section portion 625is filled with the welding material 53 therein around the fixing member52 so as to retain the fixing member 52.

Specifically referring to FIG. 5, both of the end faces 513 have theinclined faces 514 extending from the outer ends 5111 of the outer blocksurface 511 along diverging directions that are inclined with respect tothe radial line (L6) of the fixing member 52. Furthermore, both of theend faces 513 have the cut faces 515 extending respectively from theinclined faces 514 to the inner ends 5121 of the inner block surface 512along directions which are substantially parallel to the radial line(L6) of the fixing member 52. Each of the inclined faces 514 forms anangle (θ2, θ3) ranging from 10° to 80° with a line (L4, L5) which isparallel to the radial line (L6) of the fixing member 52 and whichpasses through the adjoining one of the outer ends 5111 of the outerblock surface 511.

Referring to FIGS. 4, 6, and 7, a preferred embodiment of a method forfixing the guide block 51 in the gland 62 of the seal device 6 for thestuffing box according to this invention includes the steps of:

A) Providing the gland 62 with the fixing hole 623:

The gland 62 is provided with the fixing hole 623 that extends radiallythrough the inner and outer gland surfaces 626, 627 of the gland 62. Thefixing hole 623 is stepped to form small and large cross-sectionportions 624, 625. The small cross-section portion 624 extends throughthe inner gland surface 626 to communicate with the fluid passage 621.The large cross-section portion 625 extends through the outer glandsurface 627.

B) Disposing the guide block 51 in the fluid passage 621:

The guide block 51 is disposed in the fluid passage 621.

C) Inserting the fixing member 52:

The fixing member 52 is inserted into the fixing hole 623 from the outergland surface 627.

D) Connecting the fixing member 52 to the guide block 51:

The fixing member 52 is connected to the guide block 51 by screwing.

Alternatively, the fixing member 52 can be connected to the guide block51, for example, by screwing before being inserted into the fixing hole623, and is inserted into the fixing hole 623 from the inner glandsurface 626 after the guide block 51 is disposed in the fluid passage621. This is especially performed in the case in which the fixing member52 and the guide block 51 are formed as one piece.

E) Placing the outer block surface 511 of the guide block 51 in abutmentwith the gland 62:

The outer block surface 511 of the guide block 51 is placed in abutmentwith the inner gland surface 626 of the gland 62.

F) Filling the welding material 53:

The welding material 53 is filled in the large cross-section portion 625of the fixing hole 623 around the fixing member 52, thereby retainingthe fixing member 52 in the fixing hole 623.

G) Cutting:

A portion of the fixing member 52 that extends outwardly of the fixinghole 623 is cut, followed by a grinding process to make the fixingmember 52 flush with the outer gland surface 627 of the gland 62.

Referring again to FIG. 4, in the preferred embodiment in which the sealdevice 6 is used as a dual seal device, two of the holes 622, 622′, 622″are respectively used as an inlet and an outlet for the buffer/barrierfluid. The remaining one of the holes 622, 622′, 622″ is plugged.

Referring to FIG. 8, when the rotary shaft 7 is rotated clockwise, thethird hole 622″ is plugged, and the first and second holes 622, 622′ arerespectively used as the inlet and the outlet for the buffer/barrierfluid. As indicated by the arrows in the figure, the buffer/barrierfluid flows through the first hole 622, is guided by the inclined face514 of a corresponding one of the end faces 513 of the guide block 51,flows smoothly in the fluid passage 621, and exits through the secondhole 622′. Conversely, when the rotary shaft 7 is rotatedcounterclockwise, the buffer/barrier fluid flows through the second hole622′, is guided by the inclined face 514 of a corresponding one of theend faces 513 of the guide block 51, flows smoothly in the fluid passage621, and exits through the first hole 622.

Referring to FIG. 9, when the rotary shaft 7 is rotated clockwise, thefirst hole 622 is plugged, the second hole 622′ is used as the outletfor the buffer/barrier fluid, and the third holes 622″ is used as theinlet for the buffer/barrier fluid. Conversely, when the rotary shaft 7is rotated counterclockwise, the second hole 622′ is plugged, the firsthole 622 is used as the outlet for the buffer/barrier fluid, and thethird holes 622″ is used as the inlet for the buffer/barrier fluid.

Referring to FIG. 10, when the rotary shaft 7 is rotatedcounterclockwise, the second hole 622′ is plugged, the first hole 622 isused as the outlet for the buffer/barrier fluid, and the third hole 622″is inclined relative to the first and second holes 622, 622′ and is usedas the inlet for the buffer/barrier fluid. Conversely, when the rotaryshaft 7 is rotated clockwise, the first hole 622 is plugged, the secondhole 622 is used as the outlet for the buffer/barrier fluid, and thethird hole 622″ is inclined in an opposite direction relative to thefirst and second holes 622, 622′ and is used as the inlet for thebuffer/barrier fluid.

Referring to FIG. 11, when the seal device 6 is used as a single sealdevice and the rotary shaft 7 is rotated counterclockwise, the first andthird holes 622, 622″ are plugged. In this case, the flush fluid ispassed through the second hole 622′ and is supplied into the fluidpassage intermittently. Conversely, when the rotary shaft 7 is rotatedclockwise, the second and third holes 622′, 622″ are plugged. In thiscase, the flush fluid is passed through the first hole 622 and issupplied into the fluid passage intermittently.

Referring to FIG. 12, another configuration of the guide block 51suitable for the seal device 6 of this invention is illustrated, inwhich only one of the end faces 513 of the guide block 51 has theinclined face 514 lying in a plane line (L8) that is substantiallytangent to an outer peripheral face of the rotary ring 63, and in whichthe other of the end faces 513 of the guide block 51 lies in the line(L4) parallel to the radial line (L6). The configuration of the guideblock 51 shown in FIG. 12 is especially suitable for the seal device 6in the situations shown in FIGS. 9, 10, and 11.

Referring to FIG. 13, still another configuration of the guide block 51suitable for the seal device 6 of this invention is illustrated, inwhich both of the end faces 513 of the guide block 41 have the inclinedfaces 514 extending from the outer ends 5111 of the outer block surface511 along parallel directions which are inclined with respect to theradial line (L6) of the fixing member 52. The configuration of the guideblock 51 shown in FIG. 13 is especially suitable for the seal device 6in the situations shown in FIGS. 9, 10, and 11.

In view of the aforesaid, since at least one of the end faces 513 of theguide block 51 has the inclined face 514 lying in the plane line (L7,L8) that is substantially tangent to the outer peripheral face of therotary ring 63, the buffer/barrier fluid or the flush fluid can beguided by the inclined face 514 of the guide block 51 so as to flowsmoothly in the fluid passage 621. Furthermore, since the weldingmaterial 53 fills the large cross-section portion 625 of the fixing hole623 around the fixing member 52, the fixing member 52 can be retained inthe fixing hole 623 and is not easily broken.

While the present invention has been described in connection with whatare considered the most practical and preferred embodiments, it isunderstood that this invention is not limited to the disclosedembodiments but is intended to cover various arrangements includedwithin the spirit and scope of the broadest interpretation so as toencompass all such modifications and equivalent arrangements.

1. A seal device for a rotary shaft, comprising: a sleeve for extensionof and connection with the rotary shaft; at least one gland having aninner gland surface defining a central hole for extension of saidsleeve, and a fluid passage extending annularly around said centralhole; at least one ring disposed around said sleeve within said centralhole; a guide block disposed within said fluid passage and having anouter block surface extending circumferentially and abutting against aportion of said inner gland surface, and an inner block surfaceextending circumferentially and opposite to said outer block surface,said outer block surface having two circumferentially opposite outerends, said inner block surface having two circumferentially oppositeinner ends, said guide block further having two opposite end faces eachof which connects one of said outer ends to one of said inner ends, saidinner ends subtending an angle of not larger than 90° at a center lineof said gland, at least one of said end faces lying in a plane line thatis substantially tangent to an outer peripheral face of said ring; and afixing member connected to said guide block and fixed to said gland. 2.The seal device as claimed in claim 1, wherein said fixing memberextends along a radial line that passes through said center line of saidgland, said at least one of said end faces having an inclined face lyingin said plane line and adjoining one of said outer ends of said outerblock surface, said inclined face forming an angle ranging from 10° to80° with a line which is parallel to said radial line of said fixingmember and which passes through said one of said outer ends of saidouter block surface.
 3. The seal device as claimed in claim 2, whereinsaid at least one of said end faces of said guide block further has acut face extending from said inclined face to one of said inner ends ofsaid inner block surface.
 4. The seal device as claimed in claim 2,wherein both of said end faces have said inclined faces extending fromsaid outer ends of said outer block surface along diverging directionsthat are inclined with respect to said radial line of said fixingmember.
 5. The seal device as claimed in claim 3, wherein both of saidend faces have said inclined faces extending from said outer ends ofsaid outer block surface along diverging directions that are inclinedwith respect to said radial line of said fixing member.
 6. The sealdevice as claimed in claim 5, wherein both of said end faces have saidcut faces extending respectively from said inclined faces to said innerends of said inner block surface along directions which aresubstantially parallel to said radial line of said fixing member.
 7. Theseal device as claimed in claim 3, wherein both of said end faces havesaid inclined faces extending from said outer ends of said outer blocksurface along parallel directions which are inclined with respect tosaid radial line of said fixing member.
 8. The seal device as claimed inclaim 1, wherein said fixing member and said guide block are formed asone piece.
 9. The seal device as claimed in claim 1, wherein said fixingmember is a fixing rod that has an external thread, said guide blockhaving a threaded hole extending inwardly from said outer block surface,said fixing rod being engaged in said threaded hole.
 10. The seal deviceas claimed in claim 1, wherein said ring has an outer peripheral faceformed with a plurality of annularly spaced apart recesses andprojections.
 11. The seal device as claimed in claim 1, wherein saidgland further has an outer gland surface extending around said innergland surface, and a fixing hole that is stepped to form small and largecross-section portions extending radially and respectively through saidinner and outer gland surfaces, said fixing member extending throughsaid small and large cross-section portions, said large cross-sectionportion being filled with a welding material therein around said fixingmember so as to retain said fixing member.
 12. A seal device for arotary shaft, comprising: a sleeve for extension of and connection withthe rotary shaft; at least one gland having inner and outer glandsurfaces, and a fixing hole that is stepped to form small and largecross-section portions extending radially and respectively through saidinner and outer gland surfaces, said inner gland surface defining acentral hole for extension of said sleeve, and a fluid passage extendingannularly around said central hole; a guide block disposed within saidfluid passage and having an outer block surface extendingcircumferentially and abutting against a portion of said inner glandsurface, and an inner block surface extending circumferentially andopposite to said outer block surface; a fixing member connected to saidguide block and extending through said small and large cross-sectionportions, said fixing member being received fittingly in said smallcross-section portion; and a welding material filling said largecross-section portion around said fixing member, thereby retaining saidfixing member in said fixing hole.
 13. A method for fixing a guide blockin a gland of a seal device for a rotary shaft, the gland having aninner gland surface that defines a central hole and a fluid passageextending annularly around the central hole, and an outer gland surfacesurrounding the inner gland surface, the method comprising the steps of:providing the gland with a fixing hole that extends radially through theinner and outer gland surfaces; disposing the guide block in the fluidpassage; inserting a fixing member into the fixing hole; connecting thefixing member to the guide block; placing an outer block surface of theguide block in abutment with the inner gland surface; filling a weldingmaterial in the fixing hole around the fixing member, thereby retainingthe fixing member in the fixing hole; and cutting a portion of thefixing member that extends outwardly of the fixing hole, followed by agrinding process to make the fixing member flush with the outer glandsurface.
 14. The method as claimed in claim 13, wherein the fixing holeis stepped to form small and large cross-section portions, the smallcross-section portion extending through the inner gland surface tocommunicate with the fluid passage, the large cross-section portionextending through the outer gland surface, the welding material beingfilled in the large cross-section portion.
 15. The method as claimed inclaim 13, wherein the fixing member is connected to the guide blockbefore being inserted into the fixing hole, and is inserted into thefixing hole from the inner gland surface after the guide block isdisposed in the fluid passage.
 16. The method as claimed in claim 15,wherein the fixing member and the guide block are formed as one piece.17. The method as claimed in claim 13, wherein the fixing member isinserted into the fixing hole from the outer gland surface and isthereafter connected to the guide block disposed in the fluid passage.18. The method as claimed in claim 15, wherein the fixing member isscrewed to the guide block.
 19. The method as claimed in claim 17,wherein the fixing member is screwed to the guide block.
 20. The methodas claimed in claim 13, wherein the guide block has two opposite endfaces having inclined faces extending from two circumferentiallyopposite outer ends of the outer block surface of the guide block alongparallel directions which are inclined with respect to a radial line ofthe fixing member.
 21. The method as claimed in claim 13, wherein theguide block has two opposite end faces, at least one of the end faces ofthe guide block having an inclined face and a cut face extending fromthe inclined face to one of two circumferentially opposite inner ends ofan inner block surface of the guide block.